Reiterating that preparations are in full swing for rolling out GST on July 1, the Central Board of Excise and Customs (CBEC) said on Tuesday that, along with the states, the department has increased its outreach programmes on the forthcoming indirect tax regime so as to reach the "last trader".

"Preparations are in full swing for a smooth implementation of the landmark tax reform from 1st July, 2017. The window for migration to the GSTN (GST Network) has re-opened to assist the remaining taxpayers," a statement from the Union Finance Ministry said here.

"The GST formations are being notified shortly," it added. The CBEC has got government approval to reorganise the existing Central Excise and Service Tax field formations according to the requirements of the pan-India GST regime.

As part of this reorganisation, the CBEC will be renamed as the Central Board of Indirect Taxes and Customs (CBIC).

Meanwhile, West Bengal Finance Minister Amit Mitra continued to raise serious doubts over the feasibility of the new indirect tax regime and proposed its postponement by a month or so.

"I have also added a caveat (in the GST Council meeting) that July 1 looks extremely difficult. But you cannot do frugal innovation for world's largest fiscal reform called GST. And you are going to start GST from July 1. So my submission was, let us not do frugal innovation for something which is world's largest fiscal reform," Mitra told reporters after the 16th Council meeting here on Sunday.

He said that there is no harm in postponement of the GST "by one month or so".

"That's a point I made on record. Whenever we are fully prepared to our satisfaction ... when everyone feels comfortable ... we can go ahead," he added. Union Finance Minister Arun Jaitley has stressed that traders and industry had no option but to get ready by July 1 as no postponement was on the anvil.

"Irrespective of the date at which it is to start, some people will say we are not ready. They have no option but to get ready. You require honest intent for that," he told reporters here when asked about some industry representatives seeking more time for the GST roll-out.